Japanese Patent No. 4956616 (Patent Document 1) and Japanese Patent No. 5112438 (Patent Document 2), which are the patents owned by the applicant of the present invention, each disclose a conventional example of a two-component mixing container such as a dental cement capsule. In this two-component mixing container, a powder material and a liquid material are contained in isolation from each other as two kinds of chemicals, and the powder material and the liquid material are discharged after having been mixed together in the two-component mixing container. FIGS. 19 and 20A to 20C are respectively FIGS. 10 and 11A to 11C in Patent Document 1. The structure of the conventional two-component mixing container will be described below, using these drawings. The conventional two-component mixing container includes a housing 8, a nozzle 16, a partition wall member (12, 18), a second-component containing member 13, and a piston member 19. The housing 8 includes a first cylindrical portion 10 having a first opening portion at one end thereof and a first bottom wall portion 11 closing the other end of the first cylindrical portion 10. Then, the housing 8 includes in its inside a mixing chamber 5 configured to contain a first component and to mix the first component and a second component when the second component is injected from the one end of the first cylindrical portion 10. The housing 8 also has a discharge port 23 in the first bottom wall portion 11. The discharge port 23 is configured to discharge a mixture of the first component and the second component from the mixing chamber 5. The nozzle 16 is provided at the first bottom wall portion 11 of the housing 8. A mounting structure of the nozzle 16 is configured to dispose the nozzle 16 at a first position which causes the nozzle to close the discharge port 23 before the mixture is discharged from the discharge port 23 and to dispose the nozzle 16 at a second position which allows the discharge port and a passage of the nozzle to communicate with each other when the mixture is discharged from the discharge port 23.
A partition wall member (12, 18) is slidably held in the housing 8. The partition wall member (12, 18) includes a second cylindrical portion 18 having a second opening portion at one end thereof, a second bottom wall portion closing the other end of the second cylindrical portion 18, and a partition wall portion 12 provided at the second bottom wall portion, whereby the partition wall portion slides liquid-tightly inside the mixing chamber 5. Then, the second-component containing member 13 is fitted in the partition wall member (12, 18) such that the second-component containing member 13 may rotate about an axial line X. The second-component containing member 13 includes a third cylindrical portion having a third opening portion at one end thereof and a third bottom wall portion closing the other end of the third cylindrical portion, and includes in its inside a second-component containing chamber 3 configured to contain the second component. The second bottom wall portion (12) of the partition wall member (12, 18) is formed with a first communication passage 20, and the third bottom wall portion of the second-component containing member 13 is formed with a second communication passage 21. When the second-component containing member 13 rotates about the axial line X by a predetermined angle and then the second-component containing member 13 and the partition wall member (12, 18) come into a predetermined positional relationship, the first communication passage 20 and the second communication passage 21 communicate with each other, thereby allowing the second component to flow into the mixing chamber 5. The piston member 19 includes a piston portion located at one end of the piston member 19 and an operating rod portion located at the other end of the piston member 19. The piston portion is configured to be inserted into the third cylindrical portion from the third opening portion of the second-component containing member 13 and liquid-tightly slide inside the third cylindrical portion. The operating rod portion projects out from the third opening portion.
Before an operation of mixing the first component and the second component is started, the conventional two-component mixing container maintains a holding state in which the partition wall member (12, 18) is held in a retracted position so as to form the mixing chamber 5 in the housing 8. By performing a predetermined first operation (operation of rotation about the axial line X) on the operating rod portion of the piston member 19 in this state, the first communication passage 20 and the second communication passage 21 are aligned to communicate with each other. A communication passage (comprising the communication passages 20 and 21) is thereby formed between the second-component containing chamber 3 and the mixing chamber 5. Then, after the communication passage has been formed, the piston member 19 is moved toward the first bottom wall portion 11 to inject the second component within the second-component containing chamber 3 into the mixing chamber 5 through the communication passage (comprising the communication passages 20 and 21) that has been formed. Then, by performing an operation (second operation) of rotation about the axial line X on the piston member 19, the holding state of the partition wall member (12, 18) is released. The nozzle 16 is then disposed at the second position (position where the passage of the nozzle 16 and the discharge port 23 communicate with each other) from the first position (position shown in FIG. 19). The piston member 19 is further moved toward the first bottom wall portion 11 in this state to discharge the mixture to an outside through the nozzle 16. An engagement relationship between the housing 8 and the partition wall member (12, 18) is achieved by engagement between a projection (24) and a guide groove (25). An engagement relationship between the partition wall member (12, 18) and the second-component containing member 13 is achieved by engagement between a projection (26) and a guide groove (27). An engagement relationship between the second-component containing member 13 and the piston member 19 is achieved by a projection (28) and a guide groove (29). These projections (24, 26, 28) and guide grooves (25, 27, 29) are shown in FIG. 20 (corresponding to FIG. 11 in Patent Document 1).